A joint Mass Spectrometry Facility has been created by the Department of Environmental Sciences and Engineering and Chemistry at the University of North Carolina at Chapel Hill. The long-term objectives of the Facility are to support and promote biomedical research and teaching in mass spectrometry at UNC. These objectives will be met by the specific aims of the facility: to encourage the use of mass spectrometry in the health- allied sciences by active interactions with students and faculty; to provide training in mass spectrometry via discussions and hands-on experience; to use mass spectrometry to answer questions crucial to the success of NIH-funded research discussed in more detail under the heading "Description of Research Projects of Major Users". The Facility will provide the capability of identification and structural characterization of important biomolecules, such as nucleosides and oligonucleotides, peptides and steroids as well as synthetic compounds intended for use or testing as pharmaceuticals and biological models. In addition, accessibility to highly flexible, state-of-the-art instrumentation is expected to serve as a catalyst for development of novel applications of mass spectrometry to biomedical research problems by current users and other investigators on campus. This proposal requests funds for partial support of the purchase of a VG 70S-250SEQ Hybrid Mass Spectrometer. This mass spectrometer has the capabilities of electron impact ionization, chemical ionization, fast-atom- bombardment, collisional activation, gas chromatography, high-resolution and accurate-mass measurements. The instrument will be used by NIH-funded and other researchers in the Departments of Biology, biochemistry, Chemistry, Environmental Sciences and Engineering, Medicine and Medicinal Chemistry at the University of North Carolina at Chapel Hill. The Departments of Chemistry and Environmental Sciences and Engineering and Chemistry have committed $300,000 towards the purchase of this instrument with a balance of $327,471.90 to be sought from other sources.